I took one of my dynamic webpages, viewed the source, copied all the source code, and then made two static versions of the file. One version was using the technique and the other was not. Your webpagetest.org test runs showed that the technique is coming through as a CDN. The initial connection times and DNS lookup times were almost instantaneous.

The downside I am seeing is I do not know who owns these CDN websites. I do not know if there would be downtimes, etc.